TheFaceHugger - 1 year ago 89

Java Question

So I am trying to write a program for my AP comp sci class in High School, and we are told to find the angle measures of a triangle with only the side lengths given, I have used the law of cosigns to find the first angle and am trying to use the law of sines to find the second, however it doesn't work. I have read all the other threads over this and have added the

`Math.toRadians()`

`double s1 = 0;`

double s2 = 0;

double s3 = 0;

double angles1 = 0;

double angles2 = 0;

System.out.println("Enter side 1 of your triangle");

s1 = key.nextDouble();

System.out.println("Enter side 2 of your triangle");

s2 = key.nextDouble();

System.out.println("Enter side 3 of your triangle");

s3 = key.nextDouble();

angles1 = Math.acos((s3*s3-s2*s2-s1*s1)/(2*s1*s2)); // angle from side 3

angles2 = Math.asin(Math.sin(Math.toRadians(angles1)) * s2 / s3);

angles1 = angles1 * 57.3;

angles1 = Math.round(angles1);

angles2 = angles2 * 57.3;

angles2 = Math.round(angles2);

System.out.println(" Angle 1 " + angles1);

System.out.println(" Angle 2 " + angles2);

Answer Source

Math.acos returns a value already in radians, so just remove the Math.toRadians and it will work fine:

```
angles2 = Math.asin(Math.sin(angles1) * s2 / s3);
```